how do i export face normals?
A mesh objects data contains lists for vertices, edges and polygons. Each edge and polygon has a list of vertex indices that it uses.

Python's csv.writer is included with blender's python install.

import bpy
import csv

obj_data = bpy.context.active_object.data

with open('out.csv', 'w') as csvfile:
    data = csv.writer(csvfile, delimiter=',')
    for f in obj_data.polygons:
        face_data = []
        for i in f.vertices:
            face_data += [obj_data.vertices[i].co]
        face_data += [f.normal]
        data.writerow(face_data)